Each player or instrumentalist must hear his own instrument in relation to those of others in a playing group in order that a satisfactory sound in his own instrument is produced by accurate pitch, proper volume balance, and proper tonal blend. In various or varying conditions, such as outdoor environs or halls, and/or wherever acoustics are poor or in need of certainty for the player, such production is difficult to achieve. With modern day communication equipment, such as a plurality of microphones for different kinds of instruments in a playing group, this invention provides the answer to a wind instrument player in the group and provides the need for the invention in the art.